Two protesters accused of taking explosive devices to Minnesota to disrupt the Republican National Convention are being investigated for possible links to this summer's still unsolved blaze at the Texas governor's mansion.

Department of Public Safety officials won't say whether the men - 22-year-old David McKay and 23-year-old Bradley Crowder - are suspects in the June 8 arson, which gutted the governor's mansion.

But a high-ranking state law enforcement official said today that the men, who remain in custody in Minnesota and stand accused of manufacturing Molotov cocktails for use at last week's convention, are under investigation in Texas.

Texas officials have video surveillance of a young man lighting a Molotov cocktail and using it to set the governor's mansion on fire.

The official, who spoke only on condition of anonymity because the probe is on-going, said there were "enough similar characteristics in the two cases to justify a review".

Minnesota attorney Jeff Degree said he hasn't heard of any Texas investigators meeting with McKay, his client, and that they haven't spoken about the governor's mansion case. When asked whether McKay admitted to producing Molotov cocktails for the Republican convention, Degree declined to answer.

"It's early on in the case and we haven't been able to review a lot of it," he said. "It seems pretty clear, however, that law enforcement undertook a lot of pretty aggressive actions (during the convention), not just on the street but undercover informants."

McKay and Crowder, who investigators say are connected to an Austin-based anarchist organisation called the Affinity Group, were charged in US federal court in Minnesota last week with illegally possessing Molotov cocktails.

According to a federal affidavit, the FBI in Texas began investigating the group in February 2007, and group members left Texas last month for the convention site.

Investigators allege that McKay and Crowder stopped at a Wal-Mart in St Paul to purchase Molotov cocktail supplies, which they stored at a local residence.

On an FBI audio recording taped by an informant, McKay allegedly discusses plans to throw the explosive devices at vehicles in a parking lot used by law enforcement vehicles. During the same conversation, McKay is heard saying it was "worth it if an officer gets burned or maimed", authorities allege.

When St Paul police raided the residence on September 3, officers seized gas masks, slingshots, helmets, and containers of a gasoline and oil mixture. They found eight assembled Molotov cocktails.

McKay was arrested in that raid. Crowder, whose attorney and family members could not be reached, had been arrested two days earlier for disorderly conduct.

Crowder's MySpace page where he uses the screen name Thoughtrebel, includes pictures of himself, one of which shows him crouching in front of three men carrying what appear to be Molotov cocktails. His page says he is a member of the Anarchist Collective and Anarchy in the USA groups.

On McKay's web page, which is titled Go Away, he posts pictures of himself protesting and getting arrested by the Midland county, Texas, sheriff's department.

His most recent log-in was on August 27, four days before the Republican National Convention.

The men will remain in custody in Minnesota until that state's investigation is complete, said David Anderson, a spokesman for the US Attorney's Office.

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